Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, digital cameras, digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, video teleconferencing devices, and the like. Digital video devices implement video compression techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263 or ITU-T H.264/MPEG-4, Part 10, Advanced Video Coding (AVC), and extensions of such standards, to transmit and receive digital video information more efficiently. New video standards, such as the High Efficiency Video Coding (HEVC) standard being developed by the “Joint Collaborative Team—Video Coding” (JCTVC), which is a collaboration between MPEG and ITU-T, continue to emerge and evolve. This new HEVC standard is also sometimes referred to as H.265.
Video compression techniques perform spatial prediction and/or temporal prediction to reduce or remove redundancy inherent in video sequences. For block-based video coding, a video frame or slice may be partitioned into blocks referred to as coding unit (CUs). In general, a CU has a similar purpose to a macroblock of the H.264 standard, except that a CU does not have a size distinction. CUs in an intra-coded (I) frame or slice are encoded using spatial prediction with respect to neighboring CUs in the same frame or slice. CUs in an inter-coded (P or B) frame or slice may use spatial prediction with respect to neighboring CUs in the same frame or slice or temporal prediction with respect to other reference frames.